1. Field of the Invention
This invention relates to the field of power transmission in a driveline for an automotive vehicle. More particularly, it pertains to a secondary transmission for an automotive transmission.
2. Description of the Prior Art
It is desirable to have a large range of gear ratios is an automatic transmission to accommodate the demand for various applications, such as towing. It is also desirable to increase the number of selectable gear ratios and the range therefor, to provide gear ratios to maximize fuel economy and drivability. It is desirable to provide a shifting mechanism to provide these ratios.
To drivably connect relatively rotating shafts, a mechanical synchronizer is commonly provided to synchronize the rotational speed of the shafts, an example of which is provided in U.S. Pat. No. 4,375,172. The device of the '172 patent is a relatively effective mechanism, but is produced at high cost and not able to engage over a wide speed variation.
The mechanism employed in the '172 patent includes a blocked resilient axial interconnection between a jaw clutch assembly and main shaft 23 to improve the range of engagement. As described with reference to FIGS. 8 and 9 of the '172 patent, a device according to the '172 patent provides a large amount of backlash 208 to ensure adequate initial penetration, or engagement 212 of the teeth. This excessive backlash is not desirable as it provides additional slop in the system.
It would be desirable to provide a non-blocked engagement device for engaging relatively rotating shafts and to provide such a device on a transmission.